Synthesis, reactivities, and coordination chemistry of Tris(2-isopropoxyphenyl)phosphine

Article abstract of DOI:10.1002/hc.21174

A phosphine bearing three 2-isopropoxyphenyl groups, P{C₆H₄[2-O(i-Pr)]}₃ (1), was synthesized. Phosphine 1 readily reacted with CH₂Cl₂ and ClCH₂CH₂Cl at 25°C to give the corresponding phosphonium salts [RCH₂P{C₆H₄[2-O(i-Pr)]}₃]X (2: R=X=Cl, 3: R=CH₂Cl, X=BF₄). Platinum, palladium, and rhodium complexes with ligand 1, [PtCl₂(1)₂] (4), [PdCl₂(1)₂] (5), [{PdCl(1)}₂(μ-Cl)₂] (6), and [RhCl(cod)(1)] (7) were synthesized and their structures were determined by X-ray crystallography, which revealed that ligand 1 works as a monodentate ligand in these complexes.

Full text of DOI:10.1002/hc.21174

Heteroatom Chemistry
Volume 25, Number 6, 2014
Synthesis, Reactivities, and Coordination
Chemistry of
Tris(2-isopropoxyphenyl)phosphine
Nobuhiro Takeda, Tomonori Tagawa, and Masafumi Unno
Division of Molecular Science and International Education and Research Center for Silicon
Science, Faculty of Science and Technology, Gunma University, Kiryu, Gunma 376-8515,
Japan
Received 6 March 2014; revised 17 April 2014
ing tripodal tetradentate ligands from the viewpoints
ABSTRACT:
A
phosphine bearing three 2-
groups, P{C6H4[2-O(i-Pr)]}3
of the activation of small molecules, the stabiliza-
tion of reactive species with unusual electric and
geometric structures, catalytic activities, and so on
[1–6]. Although there are many reports on tripodal
tetradentate ligands bearing nitrogen or phospho-
rus atoms, the chemistry of those bearing one phos-
phine and three chalcogenoether moieties is less ex-
plored. Such ligands are expected to show unique
structures and reactivities derived from the lability
of the coordination of chalcogenoether moieties to
transition metals and the property of phosphine as
an anchor ligand. As for PO3-type ligands, there are
many reports on transition metal complexes bearing
tris(2,4,6-trimethoxyphenyl)phosphine or tris(2,6-
dimethoxyphenyl)phosphine, which work as mono-,
bi-, tri-, or tetradentate ligands [7–12]. Some com-
plexes with tris(2-methoxyphenyl)phosphine have
been synthesized [13–18], and this phosphine ligand,
in most of its complexes, coordinates to transition
metals only by the phosphine part without the coor-
dination of the oxygen atoms. However, the studies
on other PO3-type tripodal tetradentate ligands are
relatively rare.
isopropoxyphenyl
(1), was synthesized. Phosphine 1 readily reacted
with CH2Cl2 and ClCH2CH2Cl at 25°C to give the
corresponding phosphonium salts [RCH2P{C6H4[2-
O(i-Pr)]}3]X (2: R=X=Cl, 3: R=CH2Cl, X=BF4).
Platinum, palladium, and rhodium complexes
with ligand 1, [PtCl2(1)2] (4), [PdCl2(1)2] (5),
[{PdCl(1)}2(μ-Cl)2] (6), and [RhCl(cod)(1)] (7)
were synthesized and their structures were deter-
mined by X-ray crystallography, which revealed that
ligand 1 works as a monodentate ligand in these
ꢀC
complexes.
2014 Wiley Periodicals, Inc. Het-
eroatom Chem. 25:628–635, 2014; View this
article online at wileyonlinelibrary.com. DOI
10.1002/hc.21174
INTRODUCTION
In recent years, much attention has been focused on
the chemistry of transition metal complexes bear-
On the other hand, we have recently re-
ported the synthesis and structure of group
10 metal complexes bearing a PS3-type ligand
(tris(2-isopropylthiophenyl)phosphine) [19]. In this
paper, we present synthesis and properties of
Correspondence to: Nobuhiro Takeda; e-mail: ntakeda@gunma-
u.ac.jp.
Dedicated to 77th birthday of Professor Renji Okazaki.
Supporting Information is available in the online issue at wi-
leyonlinelibrary.com.
Contract grant sponsor: Grant-in-Aid for Scientific Research (C)
from Japan Society for the Promotion of Science (JSPS).
Supporting Information is available in the online issue at
www.wileyonlinelibrary.com.
a
PO3-type ligand, tris(2-isopropoxyphenyl)-
phosphine
complexes.
(1),
and
its
transition
metal
ꢀC
2014 Wiley Periodicals, Inc.
628

Synthesis, Reactivities, and Coordination Chemistry of Tris(2-isopropoxyphenyl)phosphine 629
SCHEME 1 Synthesis of phosphine ligand 1.
FIGURE 2 ORTEP drawing of 2 with thermal ellipsoids (50%
probability). Hydrogen atoms, a counter anion, and a solvent
˚
molecule were omitted for clarity. Selected bond lengths (A):
P1–C28, 1.823(5).
The ORTEP drawing of phosphine 1 showed that
the three oxygen atoms were situated in the same
side of the lone pair of the phosphorus (Fig. 1). This
preorganized structure suggests that ligand 1 can
work as a tetradentate ligand.
FIGURE 1 ORTEP drawing of 1 with thermal ellipsoids (30%
probability). Hydrogen atoms were omitted for clarity.
Reactions of Phosphine 1 with Haloalkanes
RESULTS AND DISCUSSION
When a solution of phosphine 1 in CH2Cl2 was
stirred at 25°C for 12 h, the reaction of 1
with CH2Cl2 proceeded to give the correspond-
ing phosphonium chloride 2 as colorless crys-
tals in 85% yield (Scheme 2). The structure of
2 was determined by the 1H NMR spectrum and
X-ray crystallography (Fig. 2). It has been re-
ported that tris(2,4,6-trimethoxyphenyl)phosphine
also undergoes a similar reaction with CH2Cl2
to afford the corresponding phosphonium chlo-
ride [22]. Higher reactivities of these phosphines
compared with triphenylphosphine and tris(2-
isopropylthiophenyl)phosphine, which are stable in
haloalkanes at 25°C, can be explained by the me-
someric effect of methoxy groups. This effect results
in the increase in electron density in the phospho-
rus center of these phosphines, and the phosphorus
center having high nucleophilicity attacks the car-
bon atom of CH2Cl2.
Synthesis of Tris(2-isopropoxyphenyl)phosphine
1
After 1-bromo-2-isopropoxybenzene [20] was lithi-
ated by the treatment with butyllithium in ether
at 0°C according to the reported method [21], the
solvents were replaced by tetrahydrofuran (THF).
The reaction of resulting 2-isopropoxyphenyllithium
with PCl3 in THF at –40°C to 25°C gave tris(2-
isopropoxyphenyl)phosphine (1) in good yield
(Scheme 1). The structure of 1 was determined by
1H, 13C, and 31P NMR spectra and X-ray crystallog-
raphy.
Phosphine 1 also reacts with 1,2-dichloroethane
in the presence of NaBF4 at 25°C to afford the corre-
sponding phosphonium tetrafluoroborate 3 in 66%
yield (Scheme 2). The structure of 3 was determined
by the 1H NMR spectrum and X-ray crystallography
(Fig. 3).
SCHEME 2 Reactions of ligand 1 with dichloromethane and
1,2-dichloroethane.
Heteroatom Chemistry DOI 10.1002/hc

630 Takeda, Tagawa, and Unno
FIGURE 4 ORTEP drawing of 4 with thermal ellipsoids (50%
probability). Hydrogen atoms and solvent molecules were
omitted for clarity. Two independent molecules exist in the
unit cell. Since the structures of these two molecules are
similar to each other, only one molecule is shown. Selected
bond lengths (A) and angles (deg): Pt1–P1, 2.326(2); Pt1–
Cl1, 2.313(2); Cl1–Pt1–P1, 93.29(7); Cl1*–Pt1–P1, 86.71(7).
FIGURE 3 ORTEP drawing of 3 with thermal ellipsoids
(50% probability). Hydrogen atoms and a counter anion
˚
were omitted for clarity. Selected bond lengths (A): P1–C28,
˚
1.8214(16).
SCHEME 3 Synthesis of group 10 metal complexes with 1.
FIGURE 5 ORTEP drawing of 5 with thermal ellipsoids
(50% probability). Hydrogen atoms were omitted for clar-
˚
Synthesis of Transition Metal Complexes with
PO3 Ligand 1
ity. Selected bond lengths (A) and angles (deg): Pd1–P1,
2.342(2); Pd1–Cl1, 2.318(2); Cl1–Pd1–P1, 86.29(7); Cl1*–
Pd1–P1, 93.71(7).
When ligand 1 was treated with 0.5 molar amounts
of [PtCl2(cod)] in refluxing benzene for 24 h,
dichloridoplatinum complex 4 bearing two PO3 lig-
ands was obtained as pale yellow crystals in 86%
yield (Scheme 3). The reaction of 1 with 0.5 molar
amounts of [PdCl2(PhCN)2] in benzene at 25°C for
12 h also gave the corresponding complex 5 bear-
ing two PO3 ligands in 62% yield. On the other
hand, the reaction of 1 with equimolar amount of
[PdCl2(PhCN)2] in benzene at 25°C for 12 h re-
sulted in the formation of dipalladium complexes
6, a dimer of dichloridopalladium complex bearing
one PO3 ligand, in 57% yield.
tallography. The X-ray analyses of 4 and 5 (Figs. 4
and 5) indicated the trans configuration of the
phosphine ligands and the square planar structures
around the palladium and platinum centers. It is
suggested that no interaction exists between the oxy-
gen atoms and the metal centers, since the shortest
˚
metal–oxygen distances (Pt1···O1: 3.4993(2) A in 4,
˚
Pd1···O1: 3.534(7) A in 5) are longer than the sum
of van der Waals’ radii of metals and oxygen (Pt···O:
˚
˚
3.24 A and Pd···O: 3.15 A) [23,24], respectively.
Figure 6 shows the molecular structure of dipal-
ladium complex 6, which has syn configuration to
the Pd(μ-Cl)2Pd part and the square planar struc-
tures around the two palladium atoms. There have
The structures of these complexes 4–6 were de-
1
termined by the H NMR spectrum and X-ray crys-
Heteroatom Chemistry DOI 10.1002/hc

Synthesis, Reactivities, and Coordination Chemistry of Tris(2-isopropoxyphenyl)phosphine 631
SCHEME 4 Synthesis of rhodium complex with 1.
FIGURE 6 ORTEP drawing of 6 with thermal ellipsoids (50%
probability). Hydrogen atoms and solvent molecules were
˚
omitted for clarity. Selected bond lengths (A) and angles
(deg): Pd1–P1, 2.2413(7); Pd1–Cl1, 2.2992(7); Pd1–Cl2,
2.4293(7); Pd1–Cl3, 2.3359(6); Pd2–P2, 2.2435(7); Pd2–
Cl4, 2.2928(7); Pd2–Cl2, 2.4340(7); Pd2–Cl3, 2.3411(7);
P1–Pd1–Cl1, 88.10(3); Cl1–Pd1–Cl2, 91.05(2); Cl2–Pd1–
Cl3, 86.21(2); Cl3–Pd1–P1, 95.32(2); P2–Pd2–Cl4, 87.33(3);
Cl4–Pd2–Cl2, 91.84(2); Cl2–Pd2–Cl3, 85.99(2); Cl3–Pd2–
P2, 95.57(2).
been reported some syn-LClPd(μ-Cl)2PdClL com-
plexes which are stabilized by chelating ligands
(L-L) [25–27], however, the syn-complexes bear-
ing monodentate ligands are very rare. The syn-
structure of 6 in the crystalline state is very in-
teresting, although its reason is not clear. Since
˚
the Pd1–O1 distance [3.040(2) A] is slightly shorter
than the sum of van der Waals’ radii of palladium
˚
and oxygen (3.15 A) [23, 24] and the Pd2–O4 dis-
˚
tance [3.170(2) A] is near to this value, the existence
of very weak interaction between these atoms is
suggested.
The 1H NMR spectra of 4–6 at 25°C showed
broad peaks. The measurement at 60°C resulted in
the observation of sharp peaks in the 1H NMR spec-
tra of 4 and 5, although the 1H NMR spectrum of 6 at
60°C did not show sufficiently sharp peaks. These re-
sults suggest the restricted rotation of the P–C bonds
in these complexes (4–6).
The reaction of ligand 1 with [RhCl(cod)]2 in re-
fluxing benzene for 48 h afforded the corresponding
choloridorhodium complex 7 bearing ligand 1 and a
cod ligand in 74% yield (Scheme 4). The structure of
7 was determined by the 1H NMR spectroscopy and
X-ray crystallography (Fig. 7).
FIGURE 7 ORTEP drawing of 7 with thermal ellipsoids
(50% probability). Hydrogen atoms and a solvent molecule
˚
were omitted for clarity. Selected bond lengths (A) and an-
gles (deg): Rh1–P1, 2.3526(7); Rh1–Cl1, 2.3725(8); Rh1–
C28, 2.115(3); Rh1–C29, 2.108(3); Rh1–C32, 2.209(3); Rh1–
C33, 2.201(3); C28–C29, 1.407(4); C32–C33, 1.381(5); P1–
Rh1–Cl1, 88.89(3); P1–Rh1–C28, 96.17(8); P1–Rh1–C29,
93.04(9); Cl1–Rh1–C32, 89.97(9); Cl1–Rh1–C33, 88.39(9);
C28–Rh1–C29, 38.92(12); C28–Rh1–C32, 90.47(12); C28–
Rh1–C33, 81.47(12); C29–Rh1–C32, 81.37(12); C29–Rh1–
C33, 96.21(12); C32–Rh1–C33, 36.50(12).
The X-ray analysis showed that ligand 1 works as
a monodentate ligand and complex 7 has a square
planar structure if the alkene parts are considered
to coordinate to the rhodium(I) center with the
π-electron. The Rh–P, Rh–Cl, and Rh–C bond lengths
are normal [28], and the C28–C29 and C32–C33
bond lengths are intermediate values between single
and double bonds, suggesting the coordination of
π-electrons of the C–C double bonds to the rhodium
˚
center. Since the Rh1–O1 distance [3.421(2) A] is
Heteroatom Chemistry DOI 10.1002/hc

632 Takeda, Tagawa, and Unno
slightly shorter than the sum of van der Waals’ radii
of rhodium and oxygen (3.52 A) [23, 24], it is sug-
gested that very weak interaction exists between
these atoms.
mixture was gradually warmed to 25°C. After addi-
tion of a saturated aqueous solution of NH4Cl, the
mixture was extracted with ether/chloroform. The
organic layer was washed with brine and dried with
anhydrous Na2SO4. After the filtration, the solvents
were removed under reduced pressure. The residue
was separated by WCC (SiO2, hexane:chloroform =
1:2) to afford 1 (1.11 g, 0.112 mol, 94%) as colorless
˚
CONCLUSIONS
Tris(2-isopropoxyphenyl)phosphine (1) was synthe-
sized by the reaction of 2-isopropoxyphenyllithium
with PCl3. Phosphine 1 has high nucleophilic-
ity and readily reacts with haloalkanes such
as dichloromethane and 1,2-dichloroethane at
25°C to give the corresponding phosphonium
salts [RCH2P{C6H4[2-O(i-Pr)]}3]X (2: R=X=Cl, 3:
1
crystals. 1: Colorless crystals; H NMR (500 MHz,
3
CDCl3) δ 1.11 (d, JHH = 6.0 Hz, 18H), 4.49 (sep,
3
3JHH = 6.0 Hz, 3H), 6.78 (dd, JHH = 8.0, 8.0 Hz,
3H), 6.84 (dd, 3JHH = 8.0 Hz, JHP = 4.0 Hz, 3H), 6.88
(dd, 3JHH = 8.0, 8.0 Hz, 3H), 7.25 (dd, 3JHH = 8.0 Hz,
JHP = 8.0 Hz, 3H). 13C{1H} NMR (126 MHz, CDCl3) δ
21.7 (CH3), 70.1 (CH), 112.1 (CH), 120.1 (CH), 126.1
(d, JCP = 13.4 Hz, C), 129.2 (CH), 134.8 (d, 2JCP = 6.3
Hz, CH), 159.7 (d, JCP = 14.5 Hz, C). 31P{1H}NMR
(202 MHz, CDCl3) δ –32.9.
R=CH2Cl, X=BF4). The reaction of
1
with
[PtCl2(cod)], [PdCl2(PhCN)2], and [RhCl(cod)]2 re-
sulted in the formation of the corresponding tran-
sition metal complexes [PtCl2(1)2] (4), [PdCl2(1)2]
(5), [{PdCl(1)}2(μ-Cl)2] (6), and [RhCl(cod)(1)]
(7), in which ligand 1 works as a monodentate
ligand.
Reaction of Tris(2-isopropoxyphenyl)phosphine
(1) with Dichloromethane
A dichloromethane solution (5 mL) of phosphine
1 (122 mg, 0.279 mmol) was stirred at 25°C
for 12h. After the filtration of the reaction mix-
ture, the solvent was removed under reduced
pressure. The residue was recrystallized from
hexane/chloroform to give (chloromethyl)tris(2-
EXPERIMENTAL
General Procedures
All reactions were carried out under an argon atmo-
sphere unless otherwise noted. THF and ether were
purified by distillation from sodium diphenylketyl
before use. All solvents used in the reactions were
purified by the reported methods. Wet column
chromatography (WCC) was performed with Merck
Silica Gel 60 (70-230 mesh ASTM). The 1H NMR
(500 or 300 MHz) spectra were measured in CDCl3
or C6D6 with a JEOL JNM-λ500 or JEOL JNM-AL300
spectrometer using SiMe4 (0 ppm) as internal stan-
dards. The 13C NMR (126 MHz) and 31P NMR (202
MHz) spectra were measured in CDCl3 or C6D6 with
a JEOL JNM-λ500 spectrometer using CDCl3 (77.0
ppm) as an internal standard for 13C NMR spec-
troscopy and H3PO4 (85%) in D2O (0 ppm) as an
external standard for 31P NMR spectroscopy.
isopropoxyphenyl)phosphonium
chloride
(2)
(123.0 mg, 0.236 mmol, 85%). 2: Colorless crystals;
3
1H NMR (300 MHz, CDCl3) δ 1.05 (d, JHH = 6.0
3
Hz, 18H), 4.77 (sep, JHH = 6.0 Hz, 3H), 4.92 (d,
2JHP = 6.6 Hz, 2H), 7.18–7.22 (m, 6H), 7.44 (dd,
3
3JHH = 7.2 Hz, JHP = 15 Hz, 3H), 7.84 (dd, J = 7.5,
7.5 Hz, 3H).
Reaction of Tris(2-isopropoxyphenyl)phosphine
(1) with 1,2-Dichloroethane
A 1,2-dichloroethane solution (5 mL) of phosphine
1 (122 mg, 0.279 mmol) and sodium tetraflu-
oroborate (296 mg, 2.70 mmol) was stirred at
25°C for 48 h. After the filtration of the reac-
tion mixture, the solvent was removed under re-
duced pressure. The residue was recrystallized from
hexane/chloroform to give (2-chloroethyl)tris(2-
isopropoxyphenyl)phosphonium tetrafluoroborate
(3) (108.0 mg, 0.184 mmol, 66%). 3: Colorless crys-
tals; 1H NMR (300 MHz, CDCl3) δ 1.11 (d, 3JHH = 6.0
Hz, 18H), 3.50–3.57 (m, 2H), 3.66–3.74 (m, 2H), 4.77
(sep, 3JHH = 6.0 Hz, 3H), 7.11–7.24 (m, 9H), 7.80 (dd,
J = 7.5, 7.5 Hz, 3H).
Synthesis of Tris(2-isopropoxyphenyl)phosphine
(1)
To an ether solution (20 mL) of 1-bromo-2-
isopropoxybenzene (2.00 g, 9.30 mmol) was added
a hexane solution of n-butyllithium (1.54 M, 6.3 mL,
9.77 mmol) at 0°C. After stirring at 0°C for 1 h,
ether was removed under reduced pressure and THF
(20 mL) and trichlorophosphine (0.24 mL, 2.7 mmol)
were successively added at –40°C. The reaction
mixture was stirred for 12 h during which time the
Heteroatom Chemistry DOI 10.1002/hc

Synthesis, Reactivities, and Coordination Chemistry of Tris(2-isopropoxyphenyl)phosphine 633
TABLE 1 Crystal Data and Refinement Details for 1, 2·H2O, and 3
Characteristic
1
2·H2O
3
Empirical formula
Formula weight
Temperature
Crystal system
Space group
C27H33O3P
436.50
208(2) K
Monoclinic
P21/n (#14)
C28H37Cl2O4P
539.45
123(2) K
Monoclinic
P21/c (#14)
C29H37BClF4O3P
586.82
173(2) K
Monoclinic
P21/c (#14)
˚
a (A)
11.362(5)
15.369(6)
11.227(2)
20.605(3)
10.4614(8)
15.5486(13)
˚
b (A)
˚
c (A)
14.761(6)
90
100.615(5)
90
2533.5(19)
4
1.144
13.694(3)
90
112.927(2)
90
2917.7(10)
4
1.228
18.7462(15)
90
102.0077(10)
90
2982.5(4)
4
α (deg)
β (deg)
γ (deg)
3
˚
V (A )
Z
Dcalc (Mg m−3
)
1.307
Absorption coefficient
0.132
0.307
0.235
(mm−1
)
Crystal size (mm3)
θ range
0.30 × 0.20 × 0.05
3.33–25.50°
16,471
0.40 × 0.30 × 0.20
2.55–25.50°
19,395
0.40 × 0.30 × 0.30
3.53–25.50°
19,409
Number of reflections
measured
Number of independent
reflections
Rint
4,704
5,425
5,469
0.0884
0.0393
0.0197
Completeness
99.5%
4,704/0/286
1.006
R1 = 0.1181
wR2 = 0.2911
R1 = 0.2125
wR2 = 0.3656
0.631 and –0.520
99.7%
5,425/0/317
1.247
R1 = 0.1044
wR2 = 0.2469
R1 = 0.1064
wR2 = 0.2484
1.426 and–0.841
98.5%
5,469/0/352
1.091
R1 = 0.0409
wR2 = 0.0975
R1 = 0.0414
wR2 = 0.0978
0.690 and –0.398
Data/restraints/parameters
Goodness-of-fit on F2
Final R indices [I > 2σ(I)]a
R indices (all data)a
Largest difference peak
and hole (e A
−3
˚
)
2
aR1 = ꢀ||Fo| – |Fcࢱ/ꢀ|Fo|, wR2 = [(ꢀw(Fo – Fc2)2/ꢀw(Fo2)2]1/2
.
0.136 mmol) in benzene (5 mL) was stirred at 25°C
for 12 h. After the filtration of the reaction mixtu-
re, the filtrate was evaporated to dryness and the
residue was recrystallized from hexane/chloroform
to give dichloridobis[tris(2-isopropoxyphenyl)ph-
osphine]palladium (5) (98 mg, 0.0860 mmol, 62%).
5: Orange crystals, 1H NMR (300 MHz, CDCl3, 60°C)
δ 0.90 (brs, 36H), 4.35 (sep, 3JHH = 6.0 Hz, 6H), 6.63–
Synthesis of Dichloridobis[tris(2-
isopropoxyphenyl)phosphine]platinum (4)
A mixture of phosphine 1 (122 mg, 0.279 mmol) and
dichlorido (η-cycloocta-1,5-diene)platinum (52 mg,
0.139 mmol) in benzene (5 mL) was stirred at
reflux for 24 h. After the filtration of the re-
action mixture, the filtrate was evaporated to
dryness and the residue was recrystallized from
hexane/chloroform to give dichlorido bis[tris(2-
isopropoxyphenyl)phosphine]platinum (4) (126 mg,
3
6.79 (m, 18H), 7.22 (d, JHH = 7.5 Hz, 6H). 31P{1H}
NMR (202 MHz, CDCl3) δ 14.7.
1
0.120 mmol, 86%). 4: Pale yellow crystals, H NMR
(300 MHz, CDCl3, 60°C) δ 0.90 (brs, 36H), 4.34 (sep,
3JHH = 6.0 Hz, 6H), 6.64 (d, 3JHH = 7.5 Hz, 6H), 6.76
(dd, J = 7.5, 7.5 Hz, 6H), 7.21 (m, 12H).
Synthesis of Dichloridodi(μ-dichlorido)-
bis[tris(2-isopropoxyphenyl)phosphine]-
dipalladium (6)
A mixture of phosphine 1 (61 mg, 0.140 mmol)
and dichloridobis(benzonitrile)palladium (52 mg,
0.136 mmol) in benzene (5 mL) was stirred
at 25°C for 12 h. After the filtration of the
reaction mixture, the filtrate was evaporated
to dryness and the residue was recrystallized
Synthesis of Dichloridobis[tris(2-
isopropoxyphenyl)phosphine]palladium (5)
A mixture of phosphine 1 (122 mg, 0.279 mmol)
and dichloridobis(benzonitrile)palladium (52 mg,
Heteroatom Chemistry DOI 10.1002/hc

634 Takeda, Tagawa, and Unno
TABLE 2 Crystal Data and Refinement Details for 4·2(CHCl3), 5, and 6·2(CHCl3)
Characteristic
4·2(CHCl3)
5
6·2(CHCl3)
Empirical formula
Formula weight
Temperature
Crystal system
Space group
C56H68Cl8O6P2Pt
1377.73
153(2) K
Triclinic
P-1(#2)
C54H66Cl2O6P2Pd
1050.31
123(2) K
Triclinic
P-1(#2)
C56H68Cl10O6P2Pd2
1466.34
153(2) K
Triclinic
P-1(#2)
˚
a (A)
10.1641(8)
15.9127(13)
10.270(3)
12.197(3)
14.0926(2)
14.7747(2)
˚
b (A)
˚
c (A)
18.8640(14)
88.282(7)
85.163(6)
85.249(6)
3028.9(4)
2
1.511
2.768
0.30 × 0.20 × 0.10
2.63–25.50°
19,529
12.737(3)
111.849(3)
108.135(3)
102.208(3)
1306.8(6)
1
1.335
0.566
0.20 × 0.10 × 0.05
2.92–25.50°
8,941
18.7058(4)
70.615(3)
82.914(4)
60.342(3)
3188.75(8)
2
1.527
1.079
0.30 × 0.20 × 0.10
3.29–28.28°
27,915
α (deg)
β (deg)
γ (deg)
3
˚
V (A )
Z
Dcalc (Mg m−3
)
Absorption coefficient (mm−1
Crystal size (mm3)
θ range
)
Number of reflections measured
Number of independent
reflections
10,472
4,568
14,435
Rint
0.0336
93.0%
0.0636
93.7%
0.0259
91.2%
Completeness
Data/restraints/parameters
Goodness-of-fit on F2
Final R indices [I > 2σ(I)]a
10,472/0/661
1.480
R1 = 0.0709
wR2 = 0.1429
R1 = 0.0743
wR2 = 0.1441
0.928 and –1.000
4,568/0/296
1.063
R1 = 0.0874
wR2 = 0.2066
R1 = 0.1297
wR2 = 0.2410
0.743 and –1.086
14,435/0/685
1.181
R1 = 0.0420
wR2 = 0.0851
R1 = 0.0435
wR2 = 0.0856
1.256 and –0.795
R indices (all data)a
Largest difference peak and
−3
˚
hole (e A
)
2
aR1 = ꢀ||Fo| – |Fcࢱ/ꢀ|Fo|, wR2 = [(ꢀw(Fo – Fc2)2/ꢀw(Fo2)2]1/2
.
3
from hexane/chloroform to give dichloridobis[tris(2-
isopropoxyphenyl)phosphine]palladium (6) (49 mg,
0.040 mmol, 57%) as red crystals. 6: Red crystals, 1H
NMR (300 MHz, CDCl3, 60°C) δ 0.4–2.0 (br m, 36H),
4.64 (brs, 6H), 6.5–8.0 (br m, 24H).
3.8 Hz, 3H), 6.84 (dd, JHH = 7.5, 7.5 Hz, 3H), 7.21
(dd, JHH = 7.5, 7.5 Hz, 3H), 7.77 (brs, 3H). 31P{1H}
3
NMR (202 MHz, CDCl3): δ 17.5 (d, 1JPRh = 149 Hz).
X-Ray Crystallography of 1, 2·H2O, 3,
4·2(CHCl3), 5, 6·2(CHCl3), and 7·CHCl3
Synthesis of Chlorido(η-cycloocta-1,5-
diene)[tris(2-isopropoxyphenyl)-
phosphine]rhodium (7)
Single crystals of 1, 2·H2O, 3, 4·2(CHCl3), 5,
6·2(CHCl3), and 7·CHCl3 suitable for X-ray struc-
tural analysis were obtained by slow recrystalliza-
tion from hexane/chloroform. The crystals were
mounted on a glass fiber. The intensity data were
collected on a Rigaku R-AXIS IV++ diffractome-
ter with graphite monochromated Mo Kα radia-
A mixture of phosphine 1 (61 mg, 0.140 mmol)
and
bis[chlorido(η-cycloocta-1,5-diene)rhodium]
(69 mg, 0.140 mmol) in benzene (5 mL) was stirred at
reflux for 48 h. After the filtration of the reaction mix-
ture, the filtrate was evaporated to dryness and the
residue was recrystallized from hexane/chloroform
˚
tion (λ = 0.71070 A). The structures were solved
by direct methods (SHELXS-97 [29]), and refined
by full-matrix least-squares procedures on F2 for all
reflections (SHELXL-97 [29]). All the nonhydrogen
atoms were refined anisotropically, and all hydro-
gens were placed using AFIX instructions. The struc-
tural data are shown in Tables 1–3. CCDC num-
bers 989009 for 1, 989010 for 2·H2O, 989011 for
to
give
chlorido(η-cycloocta-1,5-diene)[tris-
(7)
(2-isopropoxyphenyl)phosphine]rhodium
(74 mg, 0.104 mmol, 74%). 7: Orange crystals,
1H NMR (300 MHz, CDCl3, 60°C) δ 1.01 (brs, 18H),
1.87 (m, 4H), 2.36 (m, 4H), 4.10 (brs, 2H), 4.45 (brs,
3
3
3H), 5.26 (brs, 2H), 6.72 (dd, JHH = 7.5 Hz, JHP
=
Heteroatom Chemistry DOI 10.1002/hc

Synthesis, Reactivities, and Coordination Chemistry of Tris(2-isopropoxyphenyl)phosphine 635
TABLE 3 Crystal Data and Refinement Details for 7·CHCl3
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Characteristic
7·CHCl3
Empirical formula
Formula weight
Temperature
Crystal system
Space group
C36H46Cl4O3PRh
802.41
153(2) K
Triclinic
P-1(#2)
˚
a (A)
10.5754(5)
12.8454(9)
˚
b (A)
˚
c (A)
14.1061(7)
86.224(5)
71.757(4)
89.165(5)
1815.94(18)
2
α (deg)
β (deg)
γ (deg)
3
˚
V (A )
Z
Dcalc (Mg m−3
)
1.467
0.843
Absorption coefficient (mm−1
Crystal size (mm3)
)
0.20 × 0.15 ×
0.15
θ range
3.44–25.50°
12,420
6,295
Number of reflections measured
Number of independent reflections
Rint
0.0244
Completeness
93.2%
6,295/0/406
1.106
R1 = 0.0378
wR2 = 0.0856
R1 = 0.0392
wR2 = 0.0865
0.719 and –1.067
Data/restraints/parameters
Goodness-of-fit on F2
Final R indices [I > 2σ(I)]a
R indices (all data)a
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Largest difference peak and hole (e
−3
˚
A
)
2
aR1 = ꢀ||Fo| – |Fcࢱ/ꢀ|Fo|, wR2 = [(ꢀw(Fo – Fc2)2/ꢀw(Fo2)2]1/2
.
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3934.
3, 989012 for 4·2(CHCl3), 989013 for 5, 989014
for 6·2(CHCl3), and 989015 for 7·CHCl3 contain
the supplementary crystallographic data for this pa-
per. These data can be obtained free of charge via
www.ccdc.cam.ac.uk/conts/retrieving.html (or from
the Cambridge Crystallographic Data Centre, 12,
Union Road, Cambridge CB2 1EZ, UK; fax: +44 1223
336033; or deposit@ccdc.cam.ac.uk).
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ACKNOWLEDGMENT
We are grateful to Professor Soichiro Kyushin,
Graduate School of Engineering, Gunma University,
Japan, for his kind permission to use his single crys-
tal X-ray diffractometer.
REFERENCES
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[29] Sheldrick, G. M.; SHELXS-97 and SHELXL-97, Pro-
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Heteroatom Chemistry DOI 10.1002/hc